Sameridine is a new class of compound with local anesthetic and analgesic properties. The clinical use of sameridine is for intrathecal administration in order to provide anesthesia for surgical purposes and prolonged post operative analgesia. In this dose finding, Phase II, double-blind study, we will study male patients undergoing unilateral inguinal hernia repair. Patients will be randomized to four different treatment groups (Sameridine 15, 20, 23 mg and lidocaine 1% 100mg). In this study, we would like to find the optimum dose and safety of sameridine during hernia repair surgery.